LASIK stands for Laser-Assisted In Situ Keratomileusis and is a procedure that permanently changes the shape of the cornea, the clear covering of the front of the eye, using an excimer laser. A knife, called a microkeratome, is used to cut a flap in the cornea. A hinge is left at one end of this flap. The flap is folded back revealing the stroma, the middlesection of the cornea. Pulses from a computer-controlled laser vaporize a portion of the stroma and the flap is replaced. There are other techniques and many new terms related to LASIK that you may hear about.

Very many people have had LASIK surgery and it has traditionally been very heavily promoted. However, given that I am still fairly active physically and would like to be able to participate in sports, there was no chance that I would opt for this procedure. Although healing may be a bit quicker and less irritating, I didn't like the thought that there is a slight but permanent risk of serious damage if for some reason you suffer physical injury and the flap disturbed.

Here is an approximately recovery timeline for healing from this type of surgery.

Phase I -- Days 1 to 3 post-op: Immediately post-op as the flap is re-positioned and the surgeon "squeegees" out excess moisture under the flap, a negative osmotic pressure is created that "sucks" the flap onto the stromal bed and holds it there. The flap is held in place fairly well at this time, barring physical trauma such as rubbing the eye or a poke in the eye. Of course, this is a very vulnerable period because any trauma to the flap could easily dislodge it, hence the importance of wearing eye shields at night and similar protections.

Phase II -- Days 4 to 14 post-op: During this period the epithelium re-generates along the perimeter of the flap, sealing and bonding the flap more securely in place. This is still a vulnerable time, but less so than in Phase I, where only osmotic pressure secured the flap.

Phase III -- Days 15 to 60 post-op: During this period the re-generated perimeter epithelium lays down a basement membrane that firmly adheres the newly regenerated epithelium to the underlying stromal bed.

Phase IV � Days 61 to 180 post-op: During this period the keratocyte cells of the stromal bed and the flap produce an adhesive protein (glycos-aminoglycan) that bonds or "glues" the flap to the stromal bed. By the 180th day, these processes have generally rather strongly secured the flap to the stromal bed. Trauma or surgical instruments can still dislodge or lift the flap, but a good deal of healing and re-bonding of the flap to the stromal bed has occurred.

Phase V -- Day 181 to 24+ months post-op: During this period collagen slowly begins to form at the interface between the flap and the underlying stromal bed.

Pro's
The natural surface of the eye is left alone and healing time seems quicker with less pain.

Con's
The flap risk never completely goes away as the cornea heals quite slowly due to lack of direct blood supply.

My Blog
I have a relatively inactive blog about my own laser surgery if you are interested.

For more detailed information and further reading, Wikipedia has a nice LASIK review.